Lyttelton Port is being accused of trying to shut out the public from having its say on the impact of pile driving on endangered Hector's dolphins.
The port has changed its design for a controversial cruise ship berth which no longer requires a resource consent.
One of those opposed to it, Genevieve Robinson, said that meant the port was no longer required to consult on the impact of the noise.
"It can actually drive them away into waters unknown, they can't hear each other acoustically, it drives them into shipping operations, fishing operations and if they're dispersed in an area they don't know - who knows what becomes of them?"
Lyttelton Port said the design was altered in order to reduce the effect on the dolphins and said piling would stop if the dolphins came close to where work was going on.